import { Meta } from "@storybook/addon-docs";

<Meta title="Documentation/Migration" />

# Migrating to the Component Library

You have been tasked with migrating a component to use the CL. What does that entail?

## Getting Started

Before progressing here, please ensure that...

- You have fully setup your dev environment as described in the
  [contributing docs](https://contributing.bitwarden.com/).
- You are familiar with [Angular reactive forms](https://angular.io/guide/reactive-forms).
- You are familiar with [Tailwind](https://tailwindcss.com/docs/utility-first).

## Background

The design of Bitwarden is in flux. At the time of writing, the frontend codebase uses a mix of
multiple UI frameworks: Bootstrap, custom "box" styles, and this component library, which is built
on top of Tailwind. In short, the "CL migration" is a move to only use the CL and remove everything
else.

This is very important work. Centralizing around a shared design system will:

- improve user experience by utilizing consistent patterns
- improve developer experience by reducing custom complex UI code
- improve dev & design velocity by having a central location to make UI/UX changes that impact the
  entire project

## Success Criteria

Follow these steps to fully migrate a component.

### Use Storybook

Don't recreate the wheel.

After reviewing a design, consult this Storybook to determine if there is a component built for your
usecase. Don't waste effort styling a button or building a popover menu from scratch--we already
have those. If a component isn't flexible enough or doesn't exist for your usecase, contact the
Component Library team.

### Use Tailwind

Only use Tailwind for styling. No Bootstrap or other custom CSS is allowed.

This is easy to verify. Bitwarden prefixes all Tailwind classes with `tw-`. If you see a class
without this prefix, it probably shouldn't be there.

<div class="tw-bg-danger-500/10 tw-p-4">
  <span class="tw-font-bold tw-text-danger">Bad (Bootstrap)</span>
  ```html
  <div class="mb-2"></div>
  ```
</div>

<div class="tw-bg-success-500/10 tw-p-4">
  <span class="tw-font-bold tw-text-success">Good (Tailwind)</span>
  ```html
  <div class="tw-mb-2"></div>
  ```
</div>

**Exception:** Icon font classes, prefixed with `bwi`, are allowed.

<div class="tw-bg-success-500/10 tw-p-4">
  <span class="tw-font-bold tw-text-success">Good (Icons)</span>
  ```html
  <i class="bwi bwi-spinner bwi-lg bwi-spin" aria-hidden="true"></i>
  ```
</div>

### Use Reactive Forms

The CL has form components that integrate with Angular's reactive forms: `bit-form-field`,
`bitSubmit`, `bit-form-control`, etc. All forms should be migrated from template-drive forms to
reactive forms to make use of these components. Review the
[form component docs](?path=/docs/component-library-form--docs).

<div class="tw-bg-danger-500/10 tw-p-4">
    <span class="tw-text-danger tw-font-bold">Bad</span>
    ```html
    <form #form (ngSubmit)="submit()">
        ...
    </form>
    ```
</div>

<div class="tw-bg-success-500/10 tw-p-4">
    <span class="tw-text-success tw-font-bold">Good</span>
    ```html
    <form [formGroup]="formGroup" [bitSubmit]="submit">
        ...
    </form>
    ```
</div>

### Dialogs

Legacy Bootstrap modals use the `ModalService`. These should be converted to use the `DialogService`
and it's [related CL components](?path=/docs/component-library-dialogs--docs). Components that are
fully migrated should have no reference to the `ModalService`.

1. Update the template to use CL components:

<div class="tw-bg-danger-500/10 tw-p-4">
    ```html
    <!-- FooDialogComponent -->
    <div class="modal fade" role="dialog" aria-modal="true">...</div>
    ```
</div>

<div class="tw-bg-success-500/10 tw-p-4">
    ```html
    <!-- FooDialogComponent -->
    <bit-dialog>...</bit-dialog>
    ```
</div>

2. Create a static `open` method on the component, that calls `DialogService.open`:

<div class="tw-bg-success-500/10 tw-p-4">
    ```ts
      export class FooDialogComponent {
        //...

        static open(dialogService: DialogService) {
          return dialogService.open(DeleteAccountComponent);
        }
      }
    ```

</div>

3. If you need to pass data into the dialog, pass it to `open` as a parameter and inject
   `DIALOG_DATA` into the component's constructor.

<div class="tw-bg-success-500/10 tw-p-4">
    ```ts
    export type FooDialogParams = {
      bar: string;
    }

    export class FooDialogComponent {
      constructor(@Inject(DIALOG_DATA) protected params: FooDialogParams) {}

      static open(dialogService: DialogService, data: FooDialogParams) {
        return dialogService.open(DeleteAccountComponent, { data });
      }
    }
    ```

</div>

4. Replace calls to `ModalService.open` or `ModalService.openViewRef` with the newly created static
   `open` method:

<div class="tw-bg-danger-500/10 tw-p-4">`this.modalService.open(FooDialogComponent);`</div>

<div class="tw-bg-success-500/10 tw-p-4">`FooDialogComponent.open(this.dialogService);`</div>

## Examples

The following examples come from accross the Bitwarden codebase.

### 1.) AboutComponent

Codeowner: Platform

https://github.com/bitwarden/clients/pull/6301/files

This migration updates a `ModalService` component to the `DialogService`.

**Note:** Most of the internal markup of this component was unchanged, aside from the removal of
defunct Bootstrap classes.

### 2.) Auth

Codeowner: Auth

https://github.com/bitwarden/clients/pull/5377

This PR also does some general refactoring, the main relevant change can be seen here:

[Old template](https://github.com/bitwarden/clients/pull/5377/files#diff-4fcab9ffa4ed26904c53da3bd130e346986576f2372e90b0f66188c809f9284d)
-->
[New template](https://github.com/bitwarden/clients/pull/5377/files#diff-cb93c74c828b9b49dc7869cc0324f5f7d6609da6f72e38ac6baba6d5b6384327)

Updates a dialog, similar to example 1, but also adds CL form components and Angular Reactive Forms.

### 3.) AC

Codeowner: Admin Console

https://github.com/bitwarden/clients/pull/5417

Migrates dialog, form, buttons, and a table.

### 4.) Vault

Codeowner: Vault

https://github.com/bitwarden/clients/pull/5648

Some of our components are shared between multiple clients (web, desktop, and the browser extension)
through the use of inheritance. This PR updates the _web_ template of a cross-client component to
use Tailwind and the CL, and updates the base component implementation to use reactive forms,
without updating the desktop or browser templates.

## Questions

Please direct any development questions to the Component Library team. Thank you!
